ATTENTION GUYS!!!

23 June 2009 (Tuesday)

Just recently i read an article from the newspaper (date: 10 June 2009).. about the MALE'S Y-CHROMOSOME.. i find it very interesting.. it's related to BIOLOGY..

Australian National University (ANU) evolutionary geneticist, Professor Jenny Graves. Professor Graves is the Head of the Comparative Genomics Research Group at the Research School of Biological Sciences at ANU and is Director of the ARC Centre for Kangaroo Genomics based at ANU and the University of Melbourne. She has received the Nobel Prize for Medicine in 1999.

Her research focuses on the evolutionary history of the human sex chromosomes, X and Y. Her team discovered that the gene on the Y chromosome thought to be responsible for testis development was not located on the Y chromosome in marsupials, which led to two of her former students identifying the correct sex-determining gene present on the Y chromosome both in placental mammals (such as humans and mice) and marsupials which branched off the evolutionary tree some 180 million years ago.

In a research paper to be published in the prestigious journal Cell this week, Professor Graves elaborates on this sex-chromosome research, and the implications of her predicted extinction of the Y-chromosome in human!!

HELLO!!!! The Y-choromosome in male human body is DEGENERATING...!!!

According to the text i read, it says that during CELL DIVISION (meiosis) in each male and female choromosome, if there's mutation occurs, the XX choromosomes are able to repair themselves (self-repairing in short), whereas the XY chromosomes are INCAPABLE in self-repairing!! Hence, it is proven that the Y-chromosomes in a male body has been degenerating since the 180 millions years AGO!!!!

According to Nature Journal, the sex chromosomes are generally believed to have descended from a pair of homologous autosomes. Suppression of recombination between the ancestral sex chromosomes led to the genetic degeneration of the Y chromosome. In response, the X chromosome may become dosage-compensated. Most proposed mechanisms for the degeneration of Y chromosomes involve the rapid fixation of deleterious mutations on the Y-chromosome.

Surveys showed that up to 15% of INFERTILE men has been found. Besides than Biotechnology, scientists have been doing researches regarding the posibilities of . Male has a very vital gene in their body called SRY (Sex-determining Region Y) is a sex-determining gene on the Y-chromosome in the therians (placental mammals and marsupials). This particular gene is interrelated with the testis development and the secretion of male sex hormones.